UK Launches World's First Trial To Test Efficacy Of Mixing Vaccines

It Will Examine Immune Responses To An Initial Dose Of Pfizer Jab Followed By A Booster Of Astra’s & Vice Versa

London: Britain on Thursday launched the world’s first trial to assess the immune responses generated if doses of the Covid-19 vaccines from Pfizer Inc and AstraZeneca Plc are combined in a two-shot schedule. The British researchers behind the trial said data on vaccinating people with the two different types of coronavirus vaccines could help understanding of whether shots can be rolled out with greater flexibility around the world. Initial data on immune responses is expected to be generated around June.

The trial will examine the immune responses to an initial dose of Pfizer vaccine followed by a booster of AstraZeneca’s, as well as vice versa, with intervals of 4 and 12 weeks. The trial will be the first of its kind to combine an mRNA shot — the one developed by Pfizer-BioNtech — and an adenovirus viral vector vaccine of the type developed by Oxford University and AstraZeneca.